1 ;;; gnus-int.el --- backend interface functions for Gnus
2 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
3 ;; Free Software Foundation, Inc.
5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
29 (eval-when-compile (require 'cl))
35 (autoload 'gnus-agent-expire "gnus-agent")
36 (autoload 'gnus-agent-regenerate-group "gnus-agent")
37 (autoload 'gnus-agent-read-servers-validate-native "gnus-agent")
39 (defcustom gnus-open-server-hook nil
40 "Hook called just before opening connection to the news server."
44 (defcustom gnus-server-unopen-status nil
45 "The default status if the server is not able to open.
46 If the server is covered by Gnus agent, the possible values are
47 `denied', set the server denied; `offline', set the server offline;
48 nil, ask user. If the server is not covered by Gnus agent, set the
51 :type '(choice (const :tag "Ask" nil)
52 (const :tag "Deny server" denied)
53 (const :tag "Unplug Agent" offline)))
55 (defvar gnus-internal-registry-spool-current-method nil
56 "The current method, for the registry.")
59 ;;; Server Communication
62 (defun gnus-start-news-server (&optional confirm)
63 "Open a method for getting news.
64 If CONFIRM is non-nil, the user will be asked for an NNTP server."
66 (if gnus-current-select-method
67 ;; Stream is already opened.
70 (unless gnus-nntp-service
71 (setq gnus-nntp-server nil))
73 ;; Read server name with completion.
74 (setq gnus-nntp-server
75 (completing-read "NNTP server: "
77 (cons (list gnus-nntp-server)
78 gnus-secondary-servers))
79 nil nil gnus-nntp-server)))
81 (when (and gnus-nntp-server
82 (stringp gnus-nntp-server)
83 (not (string= gnus-nntp-server "")))
84 (setq gnus-select-method
85 (cond ((or (string= gnus-nntp-server "")
86 (string= gnus-nntp-server "::"))
87 (list 'nnspool (system-name)))
88 ((string-match "^:" gnus-nntp-server)
89 (list 'nnmh gnus-nntp-server
91 (file-name-as-directory
93 (substring gnus-nntp-server 1) "~/")))
94 (list 'nnmh-get-new-mail nil)))
96 (list 'nntp gnus-nntp-server)))))
98 (setq how (car gnus-select-method))
102 (gnus-message 5 "Looking up local news spool..."))
105 (gnus-message 5 "Looking up mh spool..."))
108 (setq gnus-current-select-method gnus-select-method)
109 (gnus-run-hooks 'gnus-open-server-hook)
111 ;; Partially validate agent covered methods now that the
112 ;; gnus-select-method is known.
115 ;; NOTE: This is here for one purpose only. By validating
116 ;; the current select method, it converts the old 5.10.3,
117 ;; and earlier, format to the current format. That enables
118 ;; the agent code within gnus-open-server to function
120 (gnus-agent-read-servers-validate-native gnus-select-method))
123 ;; gnus-open-server-hook might have opened it
124 (gnus-server-opened gnus-select-method)
125 (gnus-open-server gnus-select-method)
129 "%s (%s) open error: '%s'. Continue? "
130 (car gnus-select-method) (cadr gnus-select-method)
131 (gnus-status-message gnus-select-method)))
132 (gnus-error 1 "Couldn't open server on %s"
133 (nth 1 gnus-select-method))))))
135 (defun gnus-check-group (group)
136 "Try to make sure that the server where GROUP exists is alive."
137 (let ((method (gnus-find-method-for-group group)))
138 (or (gnus-server-opened method)
139 (gnus-open-server method))))
141 (defun gnus-check-server (&optional method silent)
142 "Check whether the connection to METHOD is down.
143 If METHOD is nil, use `gnus-select-method'.
144 If it is down, start it up (again)."
145 (let ((method (or method gnus-select-method))
147 ;; Transform virtual server names into select methods.
148 (when (stringp method)
149 (setq method (gnus-server-to-method method)))
150 (if (gnus-server-opened method)
151 ;; The stream is already opened.
155 (gnus-message 5 "Opening %s server%s..." (car method)
156 (if (equal (nth 1 method) "") ""
157 (format " on %s" (nth 1 method)))))
158 (gnus-run-hooks 'gnus-open-server-hook)
161 (setq result (gnus-open-server method))
162 (quit (message "Quit gnus-check-server")
165 (gnus-message 5 "Opening %s server%s...%s" (car method)
166 (if (equal (nth 1 method) "") ""
167 (format " on %s" (nth 1 method)))
168 (if result "done" "failed")))))))
170 (defun gnus-get-function (method function &optional noerror)
171 "Return a function symbol based on METHOD and FUNCTION."
172 ;; Translate server names into methods.
174 (error "Attempted use of a nil select method"))
175 (when (stringp method)
176 (setq method (gnus-server-to-method method)))
177 ;; Check cache of constructed names.
178 (let* ((method-sym (if gnus-agent
179 (inline (gnus-agent-get-function method))
181 (method-fns (get method-sym 'gnus-method-functions))
182 (func (let ((method-fnlist-elt (assq function method-fns)))
183 (unless method-fnlist-elt
184 (setq method-fnlist-elt
186 (intern (format "%s-%s" method-sym function))))
187 (put method-sym 'gnus-method-functions
188 (cons method-fnlist-elt method-fns)))
189 (cdr method-fnlist-elt))))
190 ;; Maybe complain if there is no function.
191 (unless (fboundp func)
193 (error "Trying to require a method that doesn't exist"))
194 (require (car method))
195 (when (not (fboundp func))
198 (error "No such function: %s" func))))
203 ;;; Interface functions to the backends.
206 (defun gnus-open-server (gnus-command-method)
207 "Open a connection to GNUS-COMMAND-METHOD."
208 (when (stringp gnus-command-method)
209 (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
210 (let ((elem (assoc gnus-command-method gnus-opened-servers)))
211 ;; If this method was previously denied, we just return nil.
212 (if (eq (nth 1 elem) 'denied)
214 (gnus-message 1 "Denied server")
217 (let* ((open-server-function (gnus-get-function gnus-command-method 'open-server))
220 (funcall open-server-function
221 (nth 1 gnus-command-method)
222 (nthcdr 2 gnus-command-method))
224 (gnus-message 1 (format
225 "Unable to open server due to: %s"
226 (error-message-string err)))
229 (gnus-message 1 "Quit trying to open server")
232 ;; If this hasn't been opened before, we add it to the list.
234 (setq elem (list gnus-command-method nil)
235 gnus-opened-servers (cons elem gnus-opened-servers)))
236 ;; Set the status of this server.
239 (if (eq open-server-function #'nnagent-open-server)
240 ;; The agent's backend has a "special" status
244 (gnus-agent-method-p gnus-command-method))
245 (cond (gnus-server-unopen-status
246 ;; Set the server's status to the unopen
247 ;; status. If that status is offline,
248 ;; recurse to open the agent's backend.
249 (setq open-offline (eq gnus-server-unopen-status 'offline))
250 gnus-server-unopen-status)
252 (format "Unable to open %s:%s, go offline? "
253 (car gnus-command-method)
254 (cadr gnus-command-method)))
255 (setq open-offline t)
258 ;; This agentized server was still denied
261 ;; This unagentized server must be denied
264 ;; NOTE: I MUST set the server's status to offline before this
265 ;; recursive call as this status will drive the
266 ;; gnus-get-function (called above) to return the agent's
269 ;; Recursively open this offline server to perform the
270 ;; open-server function of the agent's backend.
271 (let ((gnus-server-unopen-status 'denied))
272 ;; Bind gnus-server-unopen-status to avoid recursively
273 ;; prompting with "go offline?". This is only a concern
274 ;; when the agent's backend fails to open the server.
275 (gnus-open-server gnus-command-method))
278 (defun gnus-close-server (gnus-command-method)
279 "Close the connection to GNUS-COMMAND-METHOD."
280 (when (stringp gnus-command-method)
281 (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
282 (funcall (gnus-get-function gnus-command-method 'close-server)
283 (nth 1 gnus-command-method)))
285 (defun gnus-request-list (gnus-command-method)
286 "Request the active file from GNUS-COMMAND-METHOD."
287 (when (stringp gnus-command-method)
288 (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
289 (funcall (gnus-get-function gnus-command-method 'request-list)
290 (nth 1 gnus-command-method)))
292 (defun gnus-request-list-newsgroups (gnus-command-method)
293 "Request the newsgroups file from GNUS-COMMAND-METHOD."
294 (when (stringp gnus-command-method)
295 (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
296 (funcall (gnus-get-function gnus-command-method 'request-list-newsgroups)
297 (nth 1 gnus-command-method)))
299 (defun gnus-request-newgroups (date gnus-command-method)
300 "Request all new groups since DATE from GNUS-COMMAND-METHOD."
301 (when (stringp gnus-command-method)
302 (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
303 (let ((func (gnus-get-function gnus-command-method 'request-newgroups t)))
305 (funcall func date (nth 1 gnus-command-method)))))
307 (defun gnus-server-opened (gnus-command-method)
308 "Check whether a connection to GNUS-COMMAND-METHOD has been opened."
309 (unless (eq (gnus-server-status gnus-command-method)
311 (when (stringp gnus-command-method)
312 (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
313 (funcall (inline (gnus-get-function gnus-command-method 'server-opened))
314 (nth 1 gnus-command-method))))
316 (defun gnus-status-message (gnus-command-method)
317 "Return the status message from GNUS-COMMAND-METHOD.
318 If GNUS-COMMAND-METHOD is a string, it is interpreted as a group
319 name. The method this group uses will be queried."
320 (let ((gnus-command-method
321 (if (stringp gnus-command-method)
322 (gnus-find-method-for-group gnus-command-method)
323 gnus-command-method)))
324 (funcall (gnus-get-function gnus-command-method 'status-message)
325 (nth 1 gnus-command-method))))
327 (defun gnus-request-regenerate (gnus-command-method)
328 "Request a data generation from GNUS-COMMAND-METHOD."
329 (when (stringp gnus-command-method)
330 (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
331 (funcall (gnus-get-function gnus-command-method 'request-regenerate)
332 (nth 1 gnus-command-method)))
334 (defun gnus-request-group (group &optional dont-check gnus-command-method)
335 "Request GROUP. If DONT-CHECK, no information is required."
336 (let ((gnus-command-method
337 (or gnus-command-method (inline (gnus-find-method-for-group group)))))
338 (when (stringp gnus-command-method)
339 (setq gnus-command-method
340 (inline (gnus-server-to-method gnus-command-method))))
341 (funcall (inline (gnus-get-function gnus-command-method 'request-group))
342 (gnus-group-real-name group) (nth 1 gnus-command-method)
345 (defun gnus-list-active-group (group)
346 "Request active information on GROUP."
347 (let ((gnus-command-method (gnus-find-method-for-group group))
348 (func 'list-active-group))
349 (when (gnus-check-backend-function func group)
350 (funcall (gnus-get-function gnus-command-method func)
351 (gnus-group-real-name group) (nth 1 gnus-command-method)))))
353 (defun gnus-request-group-description (group)
354 "Request a description of GROUP."
355 (let ((gnus-command-method (gnus-find-method-for-group group))
356 (func 'request-group-description))
357 (when (gnus-check-backend-function func group)
358 (funcall (gnus-get-function gnus-command-method func)
359 (gnus-group-real-name group) (nth 1 gnus-command-method)))))
361 (defun gnus-request-group-articles (group)
362 "Request a list of existing articles in GROUP."
363 (let ((gnus-command-method (gnus-find-method-for-group group))
364 (func 'request-group-articles))
365 (when (gnus-check-backend-function func group)
366 (funcall (gnus-get-function gnus-command-method func)
367 (gnus-group-real-name group) (nth 1 gnus-command-method)))))
369 (defun gnus-close-group (group)
370 "Request the GROUP be closed."
371 (let ((gnus-command-method (inline (gnus-find-method-for-group group))))
372 (funcall (gnus-get-function gnus-command-method 'close-group)
373 (gnus-group-real-name group) (nth 1 gnus-command-method))))
375 (defun gnus-retrieve-headers (articles group &optional fetch-old)
376 "Request headers for ARTICLES in GROUP.
377 If FETCH-OLD, retrieve all headers (or some subset thereof) in the group."
378 (let ((gnus-command-method (gnus-find-method-for-group group)))
380 ((and gnus-use-cache (numberp (car articles)))
381 (gnus-cache-retrieve-headers articles group fetch-old))
382 ((and gnus-agent (gnus-online gnus-command-method)
383 (gnus-agent-method-p gnus-command-method))
384 (gnus-agent-retrieve-headers articles group fetch-old))
386 (funcall (gnus-get-function gnus-command-method 'retrieve-headers)
387 articles (gnus-group-real-name group)
388 (nth 1 gnus-command-method) fetch-old)))))
390 (defun gnus-retrieve-articles (articles group)
391 "Request ARTICLES in GROUP."
392 (let ((gnus-command-method (gnus-find-method-for-group group)))
393 (funcall (gnus-get-function gnus-command-method 'retrieve-articles)
394 articles (gnus-group-real-name group)
395 (nth 1 gnus-command-method))))
397 (defun gnus-retrieve-groups (groups gnus-command-method)
398 "Request active information on GROUPS from GNUS-COMMAND-METHOD."
399 (when (stringp gnus-command-method)
400 (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
401 (funcall (gnus-get-function gnus-command-method 'retrieve-groups)
402 groups (nth 1 gnus-command-method)))
404 (defun gnus-request-type (group &optional article)
405 "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
406 (let ((gnus-command-method (gnus-find-method-for-group group)))
407 (if (not (gnus-check-backend-function
408 'request-type (car gnus-command-method)))
410 (funcall (gnus-get-function gnus-command-method 'request-type)
411 (gnus-group-real-name group) article))))
413 (defun gnus-request-set-mark (group action)
414 "Set marks on articles in the back end."
415 (let ((gnus-command-method (gnus-find-method-for-group group)))
416 (if (not (gnus-check-backend-function
417 'request-set-mark (car gnus-command-method)))
419 (funcall (gnus-get-function gnus-command-method 'request-set-mark)
420 (gnus-group-real-name group) action
421 (nth 1 gnus-command-method)))))
423 (defun gnus-request-update-mark (group article mark)
424 "Allow the back end to change the mark the user tries to put on an article."
425 (let ((gnus-command-method (gnus-find-method-for-group group)))
426 (if (not (gnus-check-backend-function
427 'request-update-mark (car gnus-command-method)))
429 (funcall (gnus-get-function gnus-command-method 'request-update-mark)
430 (gnus-group-real-name group) article mark))))
432 (defun gnus-request-article (article group &optional buffer)
433 "Request the ARTICLE in GROUP.
434 ARTICLE can either be an article number or an article Message-ID.
435 If BUFFER, insert the article in that group."
436 (let ((gnus-command-method (gnus-find-method-for-group group)))
437 (funcall (gnus-get-function gnus-command-method 'request-article)
438 article (gnus-group-real-name group)
439 (nth 1 gnus-command-method) buffer)))
441 (defun gnus-request-head (article group)
442 "Request the head of ARTICLE in GROUP."